


(Best) Worst Case Scenario

by a beta perspective (Ejunkiet)



Category: Teen Wolf (TV)
Genre: Alternate Universe - Canon Divergence, Ambiguous/Open Ending, Author's Favorite, Babysitter Stiles Stilinski, De-Aged Derek, Drama & Romance, Everybody Hates Board Games, Family Drama, High School Student Derek, M/M, Maybe sequel?, Pack Dynamics, Stilinski Family Feels, Twisted and Fluffy Feelings
Language: English
Status: Completed
Published: 2014-12-23
Updated: 2015-07-16
Packaged: 2018-03-03 00:06:40
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 3
Words: 9,366
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/2830937
Author URL: https://archiveofourown.org/users/Ejunkiet/pseuds/a%20beta%20perspective
Summary: <blockquote class="userstuff">
              <p>
  <em>"That night. What do you remember, exactly?"</em>
</p><p>
  <em>"Honestly? Not much." Derek doesn't quite meet his eyes as he says it, his grip tightening around the edges of the book in his lap. "There was an incident, a couple years ago, and it was the anniversary. I was taking a run through the woods along an animal trail, when I tripped. It hurt a lot more than it should have. Then I was here."</em>
</p><p>
  <em>“Nothing else?”</em>
</p><p>
  <em>“If you’re hoping I had some sort of clue about what spell or whatever was cast on me, then you’re asking the wrong person.”</em>
</p><p>--</p><p>Or the one where Derek moves into the Stilinski family home and Stiles deals.</p>
            </blockquote>





	1. Everybody Hates Jenga

**Author's Note:**

> _"Weres produce certain pheromones. The scent is very distinctive." He wrinkles his nose. "Your girlfriend likes you very much."_  
> 
> _Stiles mouth opens briefly, before he closes it with a quiet snap._
> 
> _"You know what? I don't even want to know."_
> 
> \--
> 
> Happy Belated Holidays to r-grimes on tumblr! Due to wonderful prompts, this has grown into a beast, and so I'm going to have to post it in two parts.

**Summary for the Chapter:**

> _"Did it really take you seven years to find me?”_

“What are you: sixteen, seventeen? You can't be that much older than me, really. This is ridiculous."

Stiles' life was so much easier a week ago, before they'd decided to stage this little rescue mission to Mexico.

Okay, so it may have been his idea - but as they'd _all_ agreed to go, Stiles is laying the blame for his current situation on the lot of them. God, he is glad to have gotten away from that place; it hadn’t taken him long to be sick to death of the heat that had cooked them alive in his jeep, and honestly, he'd be happy if he lived to never see the desert again.

"The alpha asked you to stay put, _so you are staying put._ "

"But he _didn't_ say you had to glue yourself to my side as if I were a disobedient five year old.” His features are pinched into a scowl, hands gesticulating angrily as he paces the length of the room. “Jesus. You'd think I'd start a fire the moment you left the room."

Stiles manages not to wince, but only just, instead choosing to reach out and grab the kid (the brat, the baby sour wolf, whatever you wanted to call it) by the wrist, pointedly ignoring his growl as he tugs him to a halt.

"The alpha also left _me_ in charge. That means I outrank you.” (Stiles isn’t going to examine that statement closely: he _thinks_ it does, but they never really did learn much from Derek about pack hierarchy before the shit hit the fan.) “So shut up and take your turn."

The Kid stares at him for a moment, eyes flickering over Stiles where he sits at the dining room table, before he reaches forward and knocks the carefully assembled Jenga tower onto the floor.

God, Stiles wishes he could punch him and have it actually _hurt._

"This is stupid. I don't understand why you won't just let me use your computer to send my parents an email: it won't take more than fifteen minutes, my family can pick me up, and you'd be rid of me. And I'd be away from you and your obsession with stupid fucking board games."

Derek punctuates his point with another hard shove, sending the 'Settlers of Catan' spinning across the table, managing to narrowly avoid the edge of the table by sheer fluke.

Stiles _really_ wants to punch him.

"I told you, it's not a good idea."

The Kid scoffs at that, expression twisted into a scowl as he glances back at their ruined game, flicking the last couple blocks littering the table off of the edge and onto the floor.

“Why should I listen to you, anyway?”

Stiles is reaching the end of his patience. He has no idea how he ended up with babysitting duty, but Derek – _this_ Derek – is his responsibility now, whether he likes it or not, and as much as he’d like to just say ‘screw it’ and wash his hands of him, Stiles knows that he can’t.

Whatever has happened to Derek, whatever is still _happening_ , he’s vulnerable, and Stiles is not enough of a bastard to just cut him loose.

Shit. He runs his hands through his hair, tugging at the strands as he considers his options, which are severely limited, considering his father is due to come home from his shift in little over an hour. Double shit. Well, he’ll just have to face that hurdle when it comes. If worse comes to worst, Derek will have to stay with the McCall’s, but they at least have the room now, with Isaac’s departure for Europe with Argent.

"Do I need to spell it out for you? Whoever locked you in that crypt is probably looking for you, so we're keeping a low profile. No amount of bitching is going to change that."

Derek falls silent after that, and Stiles takes advantage of the pause to reassemble the small tower of blocks, shoving himself back into his seat before staring pointedly at the Kid.

"Now, if you’re done with your little tantrum, it’s your start this time. Asshole."

\--

"How do we know this is the _real_ Derek? How can we be sure?"

Braeden shrugs; the boy propped across her shoulders tipping towards the ground before she grips his arm and tugs him back. The ki- Derek, doesn’t react; his jawline rigid and tense as he stares at the ground, although upon closer inspection, Stiles can see that his limbs are trembling, and Scott is carrying most of his weight.

Braeden’s voice drags Stiles back to the moment at hand, slightly amused as she glances over their small group, before nodding in Scott’s direction. "You’re the alpha here. Check for yourself."

Her words are directed at Scott this time, who looks between her and the group before ducking his head, sniffing indiscreetly at the teenager held between him and the mercenary. He makes a muffled noise in his throat, his eyes wide as he glances back at the rest of the group.

"There’s no mistaking it: it's him."

"But... That's not-" possible, plausible, _probable_. But Stiles recognises the shirt the boy is wearing, the small tear near the collar and the faint stains of old blood, and there's something about those eyebrows that definitely stands out in resemblance; but this kid can't be much younger than him, really, and Derek was much, much _older_.

The kid - Derek - seems just about as confused as Stiles is when he finally breaks the silence. Despite his drastic change in appearance, his voice is at least the same as it used to be.

"What is going on? Where _are_ we?"

It's Malia that replies, happy to answer a question that she knows the answer to.

"We're in Mexico. We have no idea what happened to you. One moment you were twenty-three, the next sixteen."

Derek makes a small, wounded noise in the base of his throat, his expression stricken and openly vulnerable as he breaks away from his staring contest with the ground to meet Malia’s gaze, his hands clenching into fists. "Twenty three?"

She nods, before adding, "You’re not anymore, obviously."

\--

The next day begins with Derek’s veto of all games, stating that if he had to play another round of Jenga he would, as he so delicately put it: “shove the tower so far up your ass you’ll be shitting bricks for a week.”

With that matter settled, Stiles has to turn to alternative sources of entertainment. As it turns out, Derek had been an avid follower of the Harry Potter series, although his memory cuts just short of the release of the fifth book. After the third time he’d caught Derek staring longingly at his bookshelf, he’d taken it off the shelf and tossed it across the room. He should have known better than to trust his underhand, as it dropped to the floor several feet short of his intended target, but that didn't seem to bother the kid, who'd picked it up the floor, anyway.

He hadn't said a word since, engrossed within the pages, and honestly, Stiles would take that. It was better than the constant bitching, anyway.

Stiles’ dad had been remarkably understanding about the whole de-aged-Derek thing, apparently having already acquainted himself with _this_ Derek after he’d gone missing from the veterinarian’s office the day before -- and that's a story Stiles _will_ get out of his father, and soon.

"Stiles."

He's lounging across the bed against the bookshelf, with Stiles' old copy of 'The Order of the Phoenix’ – not Stiles’ favourite of the series, if he was being honest; too _angsty_ \- slack between his fingers as he stares off at the window, expression pinched into a frown.

“Did it really take you seven years to find me?”

"Huh?" Stiles leans back to look at him, but misjudges the distance, narrowly avoiding falling off of his desk chair as he overbalanced. At the poorly stifled snort, Stiles narrows a glare across the room at the Ki- _Derek_. “What do you mean?”

"How long was I in Mexico?"

"You were only there for a couple of weeks - you were taken from your home, and it took us a little while to piece together the story. You've only really moved back to Beacon Hills again for the past year or so. Before that, you said you lived in New York."

Stiles spends a few moments clearing his desktop before he shuts down his computer – making sure that his account is locked, just in case – and picks his way over to the bed. He grabs his textbooks and highlighter along the way, situating himself against the headboard and preparing for the long haul. School was starting soon - _too soon_ , in Stiles’ opinion, and that wasn’t even taking Derek into account.

When he finally glances back over at Derek, his eyes are wide, book laying abandoned in his lap.

"New York?"

"Yeah. You never really talked about it, though.” Derek nods, a flash of _something_ making its way across his features, and god, it makes a painful kind of sense that _this_ Derek is so easy to read. He’s not sure he wants to go into this – there’s a reason they knew so little about Derek’s past, and he doesn’t want to take advantage of the situation and violate Derek’s privacy by prying further.

He can’t help the niggling curiosity, though, that pushes him to ask at least _one_ question. “Why’d you ask?”

Derek frowns, breaking away from his gaze to glance back down at the book in his lap. Stiles has already given up on the possibility for an answer and has turned back to his own textbooks when Derek’s voice carries across the room, quiet.

"It was my dream to go."

Stiles glances up to find Derek’s eyes still on the book, his shoulders hunched in a little. He looks –small, young. So very young.

His voice, when he can find it to respond, is a little softer than he intended, but he doesn’t pay it much attention. "Really? And do what?"

Derek shrugs, a small smile playing across his lips. "I don't know. Play basketball, maybe. There was a scout that was meant to come by, for the last game of the season. I was out running to build up my stamina before... before I woke up here.

"That night. What do you remember, exactly?"

The smile disappears almost as fast as it had appeared in the first place. 

"Honestly? Not much." Derek doesn't quite meet his eyes as he says it, his grip tightening around the edges of the book in his lap. "There was an incident, a couple years ago, and it was the anniversary. I was taking a run through the woods along an animal trail, half-shifted, when I tripped." 

He raises a palm, his hand steady as he runs a fingertip over the unblemished skin of his arms. His expression is indecipherable as he lifts his hand away, squeezing his fingers into a fist. 

"It hurt a lot more than it should have. Then I was here."

“Nothing else?”

Derek cuts him a sharp look, the harsh line of his mouth twisting into a scowl.

“If you’re hoping I had some sort of clue about what spell or whatever was cast on me, then you’re asking the wrong person.”

His voice breaks at the end of the proclamation, and he glances down at his hands, his teeth biting into his lip. He looks so vulnerable all of a sudden that Stiles doesn't even think about it before he reaches out and grips his hand, giving it a sharp squeeze.

"We've got your back. Don't worry, we'll figure this out."

Derek gives him a long, searching look, the muscle above his jaw flickering before he dips his head, letting out a short breath.

"Well. I don't really have a choice but to trust you, do I?"

It’s not really a question. Stiles flashes him his best crooked smile, giving his hand another squeeze.

"I’m afraid we’re all you’ve got, kid."

\-----

The next couple days are better. The pack work in shifts to keeps a watchful guard over Stiles’ house - Stiles determinedly ignoring the similarity to the events of a month or so ago - and Derek spends the nights crashing on the Stilinski's sofa. This is, of course, before the Sheriff catches him, and hustles him into the spare room on the ground floor.

It’s a bit of a mess: used for storage for the past seven years, and a terminal care room before that, and therefore neither Stiles nor his father had liked spending much time in there. Derek settles in easily enough, though, taking care to be as gentle as possible when moving the few remaining memories that the Stilinski men couldn’t bring themselves to throw away. It’s mostly sentimental crap -the oversized key they’d bought during their trip to an antiques market in the city, a box of family photo albums, the spine worn and the pages smeared with a child’s fingerprints – but Stiles can only watch him sift through the piles of faded memories for a few minutes before he has to leave to room.

Instead, Stiles heads to the kitchen to start the preparations for dinner, a Polish dish that he’d been considering making for months. The busywork of chopping up vegetables and herbs is enough to take his mind off of the things being uncovered from under years’ worth of dust, and he quickly loses himself in the monotony of food prep.

He doesn’t pay much attention to Derek when he first enters the kitchen, hovering uncertainly on the side lines for the first few minutes until Stiles loses track of him. A minute later he appears at Stiles elbow, a newly washed cutting board and knife in his hands, and Stiles shifts to make room on their limited counter space.

He can’t help but smile as Derek sidles in close beside him, blinking expectantly at Stiles as he scrubs the dirt from the root vegetables in a large bowl of water.

“What first?”

Stiles gestures with the knife to the stack of washed vegetables on the counter, and Derek accepts the handful of new potatoes, peering at the shaky scrawl of Stiles’ grandmother’s recipe before copying Stiles’ motions.

They fall into an easy rhythm, and the next half hour is spent in close, companionable silence. Stiles is surprised at how comfortable he finds it, even if Derek stands a little too close than is strictly necessary, even in the cramped confines of the Stilinski kitchen.

When they finish with the preparations and Derek still doesn’t step away, hovering at Stiles’ back as he cranks up the temperature on the crock pot, Stiles considers saying something about it -- but then Derek makes an offer to set the table. Stiles never thought he’d ever hear Derek _offer_ to help with anything, and the novelty of the action is enough to distract his mind away from it for the time being.

They’re both doing the dishes after a successful meal later – Stiles’ dad had had the biggest smile that Stiles had seen on him in _weeks_ \- when it happens again. Their arms had been brushing due to their close proximity at the sink, the heat of Derek’s side a furnace to Stiles’ left, but it hadn’t really been much of an issue up until the point that Derek had started leaning in that bit _more,_ so that his arms were now splashing water all over Stiles’ shirt, and Stiles just couldn't take it anymore.

He rinses the spatula he’s holding under running water before he turns to wield it at Derek, causing him to step back to avoid getting hit in the face.

“Is there a reason you need to stand this close to me?”

Derek glances between Stiles and the spatula, his mouth a hard line before he takes a decisive step forward, cornering Stiles against the sink.

Sputtering, Stiles goes to make another move with the spatula, but Derek catches it before he can raise it completely, using the point of contact to pull Stiles towards him, even as he tries to pull away.

“What are you-”

Derek catches Stiles’ shoulder as he tries to slide past him, pressing him back until soapy water soaks the back of his shirt and he's caged in by Derek's arms. He's immovable despite Stiles' best efforts, and Derek doesn't even seen phased, expression set with determination, as he glances between Stiles and the door, before burying his face into the juncture of Stiles’ neck and shoulder.

Stiles does not _panic_. He just expresses his anxiety in a very flail-like, loudly vocalised, non-panicked form.

One of Stiles’ flailing hands _definitely_ whacks Derek across the cheek, but he doesn’t make any move to break the damp embrace, and this – this is not what Stiles signed up for. He gives Derek’s shoulders another shove, bracing his body against the cabinet behind him to give it more weight.

“Not the neck, not the neck! Get off of me – just what do you think you’re-“

Derek pulls back, his expression undecipherable before he claps his hand across Stiles’ mouth, eyes glancing between him and the door.

“I’m not going to bite you. Stop panicking and just give me a minute.”

Before Stiles can do so much as squawk at the _nerve_ , he’s leaning in again, pressing his face into the divot beneath his throat, and all Stiles can do is stifle a giggle as he shove his wrist into his mouth. Not only is he painfully ticklish, but he also decided to forgo his morning shower in favour of an extra hour of sleep – a decision he wants to reconsider when he hears the sound of snuffling against his clothes, gusts of air blowing against his skin.

Stiles is expected to just stand there, shivering – they keep the house at a cool 65 to save on bills, which is just _fine_ when your shirt hasn’t been soaked through by a pushy werewolf - as Derek _sniffs_ him?

Stiles takes a moment to reclaim the spatula and whack Derek across the back with it.

“Asshole. You could have just _asked._ ”

Derek doesn’t respond, fingers wrapped snugly in the fabric of his shirt tightening their grip, and he gets the message – stop moving. It feels like an age before he finally loosens his grip, pulling back until Stiles can make out some of his – thankfully human - features. He doesn’t move away completely though, his expression pensive, and when he speaks, his voice is subdued.

"You smell like me. I thought I’d been imagining it."

There’s no trace of humour in Derek’s features as he says it, and well, shit.

“You can’t be serious.”

Derek shakes his head, and Stiles glances at his shirt – the only culprit – with a frown. It’s an old favourite, one that he'd actually thought he'd lost before finding it wadded up in the back of his jeep a month ago. There's nothing special about it - simple graphic tee with a suggestive slogan, something Derek had previously refused to wear on principle, preferring instead to air out his bloody, naked torso in the freezing winter air instead.

Stiles glances back up at him, gesturing to himself, and then to Derek as if to demonstrate how ridiculous Derek’s statement is.

"You must be mistaken.”

Derek just shakes his head and pushes in closer again, burying his nose into the fabric and inhaling deeply. "I’m not, though. I can smell it. It's faint, but it's there."

"How can you tell?"

"Weres produce certain pheromones. The scent is very distinctive." He wrinkles his nose. "Your girlfriend likes you very much."

Stiles mouth opens briefly, before he closes it with a quiet snap.

"You know what? I don't even want to know."

Derek takes a step back, and Stiles is finally able to flee the kitchen, leaving Derek with the rest of the washing up as he escapes upstairs to hide in his room, and dream of the days when his life wasn’t dominated by deranged, pushy werewolves.

\---

Despite that one altercation, things continue to improve between them over the next week. Somehow, in spite of all their differences, the two of them reach some sort of accord – liberally helped by a dozen hours spent killing Nazi zombies on multiplayer – and before long, they've approached a point where Stiles could even say they were starting to become friends.

Then, on a Sunday afternoon a week and a half after they found Derek, Rafael McCall pays them a visit.

The subsequent revelation of the details Stiles had omitted when Derek had asked about his past drives a wedge between Stiles and Derek, destroying whatever it was that had been building between them for the past week, and the most surprising thing about it is that Stiles realises he’s _disappointed._

At some point, he’d started to enjoy having the extra hand around the house, helping with the cooking and filling in the Scott-shaped hole in his life, however non-maliciously intended. Malia had made a deal with Eichen House to complete her current round of therapy sessions before being discharged to her father and Stiles hadn’t been able to spend more than an hour with her in weeks.

When Derek excuses himself from the impromptu non-family dinner, and Stiles is shoved against the door to his room when he follows him, Stiles can say with a hefty chunk of certainty that he probably deserved it.

Not mentioning the details of Derek’s family hadn’t been the best move, - although, _really,_ would stirring up the past do anything aside from forcing Derek to live through that tragedy again? – and Stiles is unsurprised when Derek closes off, shutting himself in the spare room with a handful of books and an aura of ‘do-not-disturb’.

His anger about the lie regarding the death of his family simmers on a constant heat for the first few days, and Stiles is sure it would have continued like this, unchanged, if Stiles’ dad hadn’t taken it upon himself to get involved.

One night, he takes each of them aside into separate room to interrogate them on the situation. Stiles is as honest as he knew how about his reasons, and whilst his dad is not quite approving of Stiles’ decision, he’s reasonable enough to understand his thought process.

Afterwards, the Sheriff talks to Derek – a tense forty minutes that Stiles spent hovering just outside, an ear pressed to the door, ready to send a premade text to their resident alpha at the first sign of trouble. Stiles isn’t expecting much, as he doesn’t have much hope that their relationship can be repaired, but he’s pleasantly surprised when Derek leaves the meeting calmer. He even asks to help Stiles with the cooking.

By the end of the week, he’s started talking to Stiles again, and it's almost as if the incident had never happened. When Stiles corners his dad about it, asking him just what went down in his talk with Derek, he just gives him a look and tells him to ask Derek himself.

Frustrated, but not desperate enough to ask Derek directly, Stiles has no choice but to let the matter go. He distracts himself with video games and trying more and more of his babcia’s recipes, with varying success.

\---

It seems like no time at all before the new school term is looming around the corner, and they're exactly nowhere near closer to finding out what happened to Derek.

When it gets to the evening before Stiles returns to classes, Derek is as restless as Stiles feels, pacing a rivet into the floor.

"I can't just keep waiting around like this. I've got to do something, Stiles." There's a soft desperation in his voice, his hands clenched into fists at his sides, irises flashing in the dim light.

"I don't know what we can do. We can't risk them finding you."

"Them? More hunters, like those who burned down my house, killed my family?" The end of the sentence slurs, the syllables disrupted by the emergence of his fangs.

When Stiles doesn't reply, or do anything to confirm or deny that statement, Derek releases a growl of frustration, turning his back to resume his pace across the living room.

"I'm sorry, Derek." He really is. But they'd agreed not to go into details - if only to protect Chris Argent, the sole remaining member of the Argent family. (Or so they'd thought.) Derek wasn't happy about it, but he'd believed them when they'd said the deaths of his family had been avenged, and that was enough for now. It was for practicality: they needed to fix him, first, before they could begin dealing with Kate.

There's a clatter of keys at the door, signalling a welcome distraction as the sheriff walks into the entryway, and it says a lot about their lives at the moment that his only response to glancing across the room to find Derek half-wolfed out is to release a sigh and drop his sidearm on the hallway table.

"Boys, we need to talk."

\--

"Dad, you can't be serious-"

"I'm the Sheriff, son; if I can't be seen upholding my own laws, then there's no reason for the people of Beacon Hills to trust me."

"It's okay, Sheriff. I'm fine with it,"

"Fine? _Fine_? What part about this is _fine?_ " Stiles waves a hand in exasperation, turning in his seat to meet the bemused eyes of his father. "We're just about to introduce one new wolf to the school, and you want to add another? We don't even know what's wrong with him, there's no way this will go well."

Stiles ignores the growl that comes from his left, watching as his father rubs a hand over his face. The creases around his eyes seem even deeper than usual when he comes up for air.

"It's not like we have much choice. Unless you know something I don’t, Stiles."

He gives Stiles a significant look, and it takes him a minute before he gets it. He gives his head a sharp shake, pinching his lips into a frown.

“You know what I know. Deaton’s not come up with anything else.”

“Then it looks like we have no choice.” The Sheriff glances towards where Derek hovers at his shoulder, almost quivering with nerves, his hands flexing at his sides. He gives him an encouraging smile. “Come with me, son. I need your help reaching Stiles’ old school supplies in the loft. I don’t think we have any gym kit that will fit you though.”

The situation is officially out of his hands, but Stiles can’t help but expect the worst as he pulls out his phone and shoots Scott off a text.

‘CALL ME ASAP. URGENT.’

They had until the end of next week to prepare before _Derek Hale_ would be joining the juniors at Beacon Hills High School. There was no way this was going to end well.


	2. Introducing the Beacon Hills Beavers

**Summary for the Chapter:**

> _"Any idea what’s wrong with him?"_
> 
> _Stiles’ grip tightens around the steering wheel._
> 
> _"None. It must be another side effect of whatever happened to him in Mexico.” He shoots Scott a glance before returning his focus on the road, levering his foot closer to the floor. His dad will understand the emergency. “You saw Deaton last. Did he mention anything about finding out how to help him?"_
> 
> _Scott shakes his head, a frown twisting down the corners of his mouth. "Not yet. He's searching all available avenues, but there's a lot of spells, a lot of curses. He says it could take as long as a month."_
> 
> _He turns in his seat, glancing back at Derek, and Stiles can guess what he's thinking, even if he doesn't say it aloud: if we have that much time._  
> 

"What happened to the Beacon Hills basketball team?"

The entire situation has officially verged a little too close to B-film territory for Stiles’ liking. Unlike Michael J. Fox’s first day at school as an actualised werewolf, though, there are no furry accidents, or any incidents at all, for that matter.

In fact, despite a few little hiccoughs involving the school dress code (Malia, who preferred to have as little clothing as possible chafing against her skin) and the changed layout of the high school (Derek - apparently the English rooms had rotated to the other side of the main building), the first week of school goes better than Stiles had expected.

It’s weird seeing Derek in this environment, making jokes, interacting with the pack just like any other individual in a group of young people – it highlights the differences between this Derek and _their_ Derek. This Derek is affable, open, willing to share a wry joke or two in class--

“Stiles. _Stiles.”_

\--and willing to snap his fingers in Stiles’ face, _repeatedly_ , until he gets his attention. Stiles slaps at the offending hand, managing to bite out a, “ _what?”_ as he shoots a displeased frown in Derek’s direction, who is decidedly unfazed. “What, asshole?”

“The basketball team.”

"We play lacrosse here."  
  
Derek gives him a look before turning back to the school noticeboard, continuing to peruse the mess of brightly coloured flyers that Stiles doesn’t have the heart to tell them are all at least three months old. “I couldn't find any signup sheets for the Beacon Hills Beavers. Do they still play?"  
  
"I don't know. You'd have to ask the coach."  
  
"Who is?"  
  
"Dead. Killed during the string of garrotte murders at the high school last fall."  
  
Derek shoots him another look, this time coupled with furrowed brows and his patent frown. What? Stiles is being _helpful_. "And no one replaced him?"  
  
"It's difficult to recruit new staff at a high school that has been the center of most of the high profile murders in this city for the last year. Even if half of those have been ruled as animal attacks." Stiles lets out a laugh. "To be honest, it's surprising that anyone actually lives here, anymore."

Derek huffs out a breath, before swivelling on his heel and storming down the hall. Stiles gives it a moment before following, knowing that Derek will wait for him by his jeep, but also understanding that as with any other teenage, Derek would need his space.

\--

Despite the semblance of normalcy that falls over the Stilinski household over the following few weeks, Stiles is under no illusion that this will last. They still haven't gotten any closer to determining the cause of Derek's weird healing ability that seems to counter his strength, and the way he tires easily, although he never states it explicitly, is an indicator of worse things to come. Stiles has enough experience spotting exhaustion in a recalcitrant, stubborn Sheriff that it doesn’t take him long to pick up the signs, even though Derek has been grabbing over nine or ten hours of sleep each night.

Stiles drops by Deaton’s regularly, making do with text messages and the occasional phone call when he can’t find the time to visit in person. Each time, Deaton promises he’ll get in contact the second that something comes up, but he always quick to respond, even if he can’t supply much more information.

Derek gets along well with the rest of their group, seemingly in awe of Lydia – and whilst Stiles wouldn’t blame him on a principle, it’s her abilties that have Derek fascinated, and it's through their shared discussions that Derek reveals the extent of of his mythological lore. He also shares tidbits of werewolf lore, little details about pack dynamics and what pack means to members, information that is simultaneously enlightening and intimate. It’s easy to see why older Derek – _their_ Derek - hadn’t elaborated on them: there’s a lot of close contact and time spent together just to bond, curled up on the sofa as Derek recites some of his favourite fables from when he was a kid.

Malia remains largely scarce during these periods. Stiles asks about it, once, but he doesn’t push it after her initial evasion. There are lots of different reasons why this sort of bonding would be an issue for her after spending the last eight years of her life alone in the woods, and he can understand her need for space while she adjusts to the changes in her life.

She drops by the last night of the week, the first time he’s seen her outside of class since school started. Stiles only knows about her arrival due to Derek's reaction: spine stiffening as he turns his face towards the ceiling in the vague direction of Stiles' bedroom.

His head cocks to the side, glancing between the spot on the ceiling and Stiles, his expression unreadable.

"Malia's here."

Stiles can’t help the smile that curves at the edges of his mouth, trying to play it off with a casual shrug. "She drops by occasionally. We study together."

"Study. Right."

"That's what we're doing, aren't we?" Stiles gestures at the papers and books surrounding them, and Derek rolls his eyes at him, slamming his book shut.

"I should go."

He’s gone before Stiles can think of a response to that, the door the bedroom downstairs swinging shut neatly behind him with a sharp click.

\--

"You smell like Derek."

"That’s not particularly surprising; we spent the day together."

"Hmm." She contemplates this for a moment, her gaze thoughtful, before Stiles has a handful of girl nuzzling into the skin of his neck, the edge of her teeth making him shiver. She pulls back before he can ask her what that was, exactly, lips curved into a small, delicate smile. "Okay."

\--

Things had been going too well.

It’s not like Stiles couldn’t have seen this coming. He’d grown complacent; Derek had settled in at school, they hadn’t seen hide or hair of Kate, and it had quietened down to the point that it seemed as if they were finally getting a well-deserved break.

They’re at school – in economics class, in fact - when the metaphorical shit hits the fan.

“Stilinski!" Finstock's shout is short and brusque, which wouldn’t be unusual, normally, if it weren’t for the fact that Stiles hadn’t actually been doing anything wrong, or anything at all, really. He glances up from his notes to find Finstock standing to his left, arms crossed tightly as he glares at the person at the desk adjacent to him -Derek - who’s glaring back with narrowed eyes and barely contained contempt.

Stiles is about to make a comment asking how on _earth_ Coach could ever get him confused with someone else, when Finstock’s attention shifts abruptly back to him, his lips pursed into a tight frown. He flicks his eyes between Stiles and Derek, bringing up his clipboard to squint at the class register.

"Your cousin – Miguel? - looks like he's about to pass out."

Stiles looks back to find Coach is right: Derek looks terrible, his skin pale, sweat seeping through the thin layers of Stiles' borrowed shirt. Now that he knows what to look for, Stiles can see that his grimace is one of pain, not of annoyance with irritating teachers.

He hisses the curse under his breath, leaning closer to grab at Derek's arm, but he doesn't even seem to notice, listing to the side with the movement, until Stiles has to tighten his grip to prevent him from falling off the desk.

Double shit.

Stiles curses again, ignoring the disapproving noise that comes from the direction of Finstock as he lurches past his desk to catch Derek's arm before he hits the floor. It's a close one, but he manages it, propping Derek up with one shoulder as Finstock hovers uncertainly behind him, clipboard dangling from his fingertips as he shoots a look between Stiles and Derek.

"Sorry, Coach. He's, uh, anaemic. He must have forgotten to take his blood pressure medication this morning." Scott is watching them closely from his seat on the otherside of the classroom, his eyes creased with worry as Stiles finds himself taking more and more of Derek's weight. Stiles glances back to find Finstock wearing a similar expression, and seizes the opportunity. "He doesn't have a car; he came in with me this morning. Can I take him home?”

"Yeah, yeah, sure." Finstock looks uncomfortable, fiddling with the register as Scott finally gets to his feet, helping Stiles with the weight. "Scott, you go with him. Take the rest of the day off -- just make sure he's okay."

It's uncharacteristically good of Finstock, but Stiles suspects it has something to do with the fact he doesn't want to deal with a dead student in his classroom. He'll take what he can get though, and nodding his agreement, he and Scott half-carry, half-drag Derek out of the classroom and towards the parking lot. Getting Derek into the jeep is an interesting experience, but after a few failed attempts, they manage it, Scott riding shotgun as Stiles fires up the jeep and takes them home.

"Any idea what’s wrong with him?"

Stiles’ grip tightens around the steering wheel.

"None. It must be another side effect of whatever happened to him in Mexico.” He shoots Scott a glance before returning his focus on the road, levering his foot closer to the floor. His dad will understand the emergency. “You saw Deaton last. Did he mention anything about finding out how to help him?"

Scott shakes his head, a frown twisting down the corners of his mouth. "Not yet. He's searching all available avenues, but there's a lot of spells, a lot of curses. He says it could take as long as a month."

He turns in his seat, glancing back at Derek, and Stiles can guess what he's thinking, even if he doesn't say it aloud: if we have that much time.

Derek lets out another low moan, and Stiles inches his foot closer to the ground, drowning anymore attempts at conversation with the roar of the engine.

\--

After they've settled an unconscious Derek on the couch, they have an unhelpful conversation with Deaton, before finally settling on the advice of Melissa McCall, working on raising his body temperature and getting as many fluids into him as possible.

They bundle him in sheets, and Stiles intersperses glasses of water with shots of orange juice to raise his blood sugar level as Derek shivers, and it doesn’t take long before the sheets are soaked in sweat.

Scott can't stay long – he’s only just picked up his grades, and if he wants to achieve his dream to go to veterinary school, he can’t afford to let them drop again - and he leaves shortly after making Stiles promise to call him if anything changes. Stiles finds himself alone with a sleeping werewolf. It takes two linen changes for the tremors to finally die down; Derek doesn't stir, despite the heavy lifting, and Stiles tries not to think about what that means.

He distracts himself with video games for the first couple hours, and the next few rehearsing his speech in case his father comes home in Sheriff Mode and ask about speeding tickets. He’s perched himself on the arm of the couch, legs splayed on either side as he speeds through his third play through of this particular rpg when Derek stirs beside him, uttering a small groan.

A moment later, his eyes flicker open, and Stiles is relieved to see them green and clear, no longer the cloudy, delirious mess they’d been earlier.

“Stiles..?”

“Holy shit.” He drops his controller onto the back of the couch, wincing as it unbalances and slides off, ricocheting off the floor. “Derek, are you – are you okay?”

Derek gives him a tight smile, wincing against the sudden brightness as Stiles shines a light in his eyes before making a swipe for Stiles’ handheld torch. Stiles takes it as a good sign.

“I think so. Just… what happened?”

“You practically passed out in class. Finstock had Scott and I take you home.” Derek nods, but he still looks a little pale, and his arms tremble where they support his weight. “Are you sure you’re feeling okay?”

“Yeah.” He tries to sit up, managing to lift most of his upper body before he curses and lowers himself back down, face twisted into a muted grimace. “Maybe not.”

Stiles gets to his feet, moving to the kitchen to refill a glass of orange juice. He fills it too close to the brim and has to take a sip to prevent it from spilling over the sides before he pads carefully back into the other room. He hands it off to Derek with a smile, perching once more against the arm of the couch. “Deaton’s working on it.”

“The veterinarian hasn’t had much luck so far.”

“Unfortunately, he’s all we’ve got.”

Derek lets out another small groan, managing a weak smile. “Great. That’s just great.”

Stiles hovers awkwardly, eyes flickering between Derek and the couch cushions, at a loss for what to do next. He’s done all that he can do, and he knows that Derek should rest, but he also doesn’t want to leave him alone, in case there are any more complications, and they need to get him to the hospital.

The silence has been going on for far too long, and feeling awkward, Stiles has just made up his mind to leave and come back later, when Derek clears his throat, pulling on his hand to get his attention.

“Can you stay?”

“Stay?”

“Until I fall back asleep. The company – helps.”

He keeps hold of Stiles’ hand, using the leverage to pull him closer when Stiles inclines his head in an awkward nod. Stiles doesn’t quite know what to expect when Derek drags him practically onto his lap, manoeuvring him until they’re lying side by side. Derek rests his hand tentatively against Stiles’ shoulder, wriggling down in the sheets until he can tuck his face behind it.

His breath is a soft brush of air against Stiles side, the rhythmic rise and fall of his chest soothing with the warmth underneath the sheets, and combined, it doesn’t take long for Stiles to drift off into sleep.

\--

When Stiles wakes up the next morning, his back is a mess of aching knots and muscles, and Derek is nowhere to be seen. There’s a brief moment of panic, where his thoughts are flooded with the Calaveras and shotgun shells filled with wolfs bane – before Derek walks in from the kitchen, a plate of breakfast food in each hand.

At Stiles’ stare, he gives a shrug, walking over to the sofa and setting the plates on the breakfast table before sliding into the small spot between Stiles and the end of the sofa. He hands Stiles a set of cutlery, which he takes gratefully, digging in with the abandon of a teenager who has forgotten to eat for maybe half a day - and hey, he was stressed, okay?

After they’ve eaten and they’re lazing on the sofa, a terrible made-for-TV movie from the Sci-Fi channel playing in the background, Derek finally speaks, his hand curled around Stiles foot where it’s resting in his lap.

“I wanted to thank you. For taking care of me.”

He's not looking at Stiles, his eyes carefully trained on the flickering motion of the TV, so Stiles doesn't bother to try to catch his gaze. Instead, he carefully pushes himself upright, extricating his foot from Derek's lap, until he can move further along the couch to settle beside him, shoulder brushing into Derek's. If the way that he relaxes is of any indication, the thin layer of tension that had been building there since he'd woken this morning finally falling away, then Stiles had guessed right -- the pack had always been comforted by tactility, and as he'd long suspected, Derek was the same.

“It’s not a problem, really. It’s sort of our thing. I take care of you, you save my ass from being monster chow." Stiles glances at Derek at that, lips twisting into a small smirk. "You could say it’s a mutually beneficial arrangement.”

The kid-Derek lets out a half-laugh, half-snort, shaking his head even as he presses his shoulder into Stiles', a solid, comforting gesture that let Stiles know what he was feeling even if he didn't feel the need to articulate it. “I know. But I just wanted to say it.”

And Stiles appreciated it. He really did. “You’re welcome.”

\--

They have a few days warning - strange sightings and animal killings in the next town over – before the Berserker’s finally descend on Beacon Hills.

From there, it doesn't take long for Kate to find them. Stiles doesn't know how much Derek understands about the situation, or whether or not he can recognise the monster that Kate has become, but he doesn’t stop to check, just grabs Derek's hand and pulls him from the fighting.

They were ambushed at the school, the first of the Berserkers crashing through the narrow hall of the locker room just after lacrosse practice, and it was only through some creative thinking on Stiles' part using the resources around them that they had managed to narrowly escape the confrontation. A locker to the face, it turns out, is enough to stall one of the brutes, at least for a little while.

He can hear Scott's howls in the distance as he yanks Derek behind him, feel the changes against his palm as the sound forces him to shift, but he doesn't stop running, his pace steady as they make their way through the school.

Derek's grip remains tight around his hand, careful to keep his claws angled away as he overtakes him, shouldering through the front doors with Stiles at his back (Stiles forgets that this was his school too, that he knows the halls as well as he does), and finally, their out, stumbling across the stones steps and onto the lawn below.

They take a second to breathe, but it's short lived -- their period of brief respite rudely interrupted by a crash as the front doors to the high school are kicked off their hinges, and Derek’s pulling him forward by the hand again, dragging him towards the school sign – or rather, where the school sign _used_ to be. Instead of the large concrete block cheerily welcoming you to the hell mouth, there's a large set of stairs descending into the ground, dark and foreboding behind a veil of shadow -- the very same set of stairs that Derek seems hell bent on dragging them towards.

“What the _hell?”_

Derek tugs at him as he slows, pulling him forward. “Come on, it’s _safe_. It’s my family vault. They won’t be able to get us in there.”

Stiles opens his mouth to ask again, as just _what_ , but whatever he’s about to say is lost to the wind as Derek suddenly yanks him back onto the lawn, sending him head-over-heels into the dirt. There's a thud and a loud crack behind him in the place where he'd just stood, and he glances back to see splintered concrete and the meaty fist of an oncoming Berserker that had been aimed at him, and _\-- dear sweet jesus,_ the impact crater is just about the same size as his head.

Stiles wastes no time in scrambling to his feet, scanning the immediate vicinity for further incoming attacks. Shit. _Shit._

Derek's snarl is loud and vicious as the Berserker swings again and misses, sending chips of rock flying where it collides with the school sign instead of Derek's face, and Stiles can't picture what the wound would look like if one of those attacks actually connected.

“Stiles – go! Into the vault, I’ll let you out.”

It says a lot about how much Stiles trusts Derek that there is no doubt in his mind that Derek will keep that promise, but he also can’t, _won’t,_ leave Derek like this; not when they don’t even know what’s happening to him, or what caused him to collapse a week ago

Derek lets out another snarl, ducking under a long swipe of claws to dig his own into the Berserker’s chest. His eyes shine brilliant blue as he throws a glance over his shoulder back at Stiles.

“Please. I couldn’t take it if I’m the reason you got hurt. I’ll be fine, just please -- go into the vault.”

“But-”

Derek lets out a growl of frustration before he dives forward, wrapping a hand around Stiles’ wrist as he drags him down the short flight of stairs, kicking at the door until it falls open in a screech of rusted metal.

“Derek, seriously, you can’t just expect me to leave you like this.”

Derek’s mouth twists into a wry grin around a mouthful of fangs. “That’s why I’m not asking.”

Stiles eyes narrow, but when he opens his mouth to let out a retort, Derek moves forward, and takes that option away from him with one simple move.

He kisses him.

It’s not what you would expect of a first kiss: there’s no hesitance, no tentative brush of lips as both parties hold themselves back. It’s nothing like that. It’s insistent and desperate all in one, coaxing at Stiles’ mouth until his lips part, and then suddenly he’s kissing him back with just as much enthusiasm, just as much energy, and holy shit, how had Stiles missed this before?

 _Derek._ It simultaneously makes _no sense_ and _too much_ _sense_ for him to handle right now.

The kiss breaks too soon for either of them. Derek is smiling, even as he untangles Stiles’ hands from his hair – he doesn’t even know when he’d done that – and brushes his hands along the back of his neck. Stiles takes a breath, unsure of when exactly he'd started holding it, before whispering "fuck it," and pressing forward again, recapturing Derek's mouth as he takes his time to map out the shape of his lips, his mouth, the shuddering of his chest beneath his fingers.

They breathe together when they break apart, huddled close within the shadows leading down into the vault as the sounds of the ongoing battle begin to filter through their little bubble of calm.

“How long?”

It’s not a complete question, but Derek gets what he’s trying to say, a small smile quirking his lips as he huffs out a laugh.

“A while, I think. There were clues, but they were only really obvious to those born wolves.”

Derek pushes him back, his hands gentle but insistent. Stiles blinks back at him, not quite understanding as he reaches for him automatically, but he’s not fast enough –the door shuts between them, the sound of metal hitting stone loud in the abrupt silence, leaving Stiles alone in the dark vault.

“Fuck.”

\--

The next time Stiles sees Derek, he’s no longer sixteen.

\--

It doesn’t take long for things to return to a semblance of normalcy.

Derek doesn’t mention the spate of time that he’d spent living in Stiles’ house, and Stiles doesn’t bring it up either, even with his dad’s broken off questions and long, contemplative glances.

And it’s fine. It is. Really.

“It’d be more convincing if you didn’t need to keep saying it, over and over.”

Stiles startles, jerking so hard that the book he’d been balancing on his knee flies up to hit him in the face. He lets out a barely stifled moan, gesturing blindly in the vague direction of his creeper girlfriend with an incriminating finger.

“Jesus, Malia.”

She shrugs. “I’ve been here a while. You didn’t notice. Stiles, you’re anything but subtle. Luckily for you, Derek’s the same. Or, he was when he was a kid.”

“What do you mean by that?”

She gives him a long, hard look, and the silence drags on before she finally glances away.

“I’m not blind, or stupid. You both care a lot for each other, more than either of you realise, but neither of you will say it out loud. In my book, that makes you both idiots.”

Her shrug is nonchalant as she breaks into a toothy smile, coming up behind him to wrap her arms around him as he leans back into her touch.

“But you’re my idiot. I’m tired. Let’s go to sleep.”

**Notes for the Chapter:**

> IT'S FINALLY DONE. Dear god, this should have been posted a month ago, but the real world got in the way. I did not expect to be working in a new job overseas when I applied for these exchanges. o___o'
> 
> find me at my [main](http://ejunkiet.tumblr.com) / [teen wolf](http://abetaperspective.tumblr.com) blog!


	3. Deleted scene

**Summary for the Chapter:**

> _"We've got your back. Don't worry, we'll figure this out."_   
>  _Derek gives him a long, searching look, the muscle above his jaw flickering before he dips his head, letting out a short breath._
> 
> _"Well. I don't really have a choice but to trust you, do I?"_
> 
> _It’s not really a question. Stiles flashes him his best crooked smile, giving his hand another squeeze._
> 
> _"I’m afraid we’re all you’ve got, kid."_

**Notes for the Chapter:**

> This deleted scene has been sitting in my files for a while..! Thank you for all the comments and feedback on this fic!

The tone in the room is more sombre after that. Derek returns to his book, fingers curled around the spine of Stiles’ battered copy of Harry Potter and Stiles goes back to his notes. It's only later when Stiles has buried himself within his notes and is actually starting to get somewhere that the situation changes. Stiles is focused on memorising the steps of a particularly difficult mathematical proof when Derek finally moves, closing his book and getting to his feet, stretching widely in the late afternoon sun. Stiles is happy to ignore him as he makes his approach, steps muted by the thick carpeting that lines the upstairs, until Derek lets out an indignant snort right next to his ear.

“I _knew it.”_

Stiles pencil slips in his hand, jabbing into his textbook, breaking the lead with a neat _snap_. _“Jesus-fucking-_ Christ, Derek!”

“I recognise the homework you’re doing.” Derek is a persistent pressure against his shoulder, completely ignoring the noises Stiles is making as he leans forward to jab a finger at the page. His gaze alternates between Stiles and the paper, narrowed and deliberate. “You know what that means, right?”

Flicking the shattered fragments of pencil lead off of his notebook – and managing to smear half of it over his already patchy notes - Stiles doesn't bother to deign that with a response. 

“It means we’re in the same year, and it’s extremely hypocritical for you to be calling me ‘kid’.”

 _That_ catches Stiles attention. There’s a muted triumph in Derek's tone, his expression twisting to take on a determined edge as he eyes the page, arms crossed neatly in front of his chest - and it appears Stiles has struck a nerve.

“I see.”

And Stiles – Stiles has never been mature, let’s face it. He knows when he’s acting like a little shit. He pushes back from the headboard, making a big show of glancing Derek up and down, and ignoring the dirty look it earns him - if glares were lethal, Stiles would have been six feet under a long time ago. “ _Really?_ ”

Derek reaches over to shove at him, and being the ungainly lanky teenager he is, he's sent ricocheting off towards the edge of his bed. It’s only through some creative manoeuvring that he manages to recover his balance in time before he hits the floor.

_"Dick."_

Once he’s reinstated himself at the head of the bed, he waits until Derek has reached for the book again before he makes his countermove. It's playing dirty, but it takes Derek completely unawares when Stiles catches him in a full body tackle- and although it may not be the most dignified method of taking down an opponent (offensive moves had never been Stiles' speciality) it's effective in that it earns Stiles a moment with the upper hand. Scrambling to make the most of his advantage, he grabs Derek by the collar and shoves the boy's face against his armpit, (for leverage, obviously) as he runs his fingers along the seam at the back. Reaching an edge, he yanks the shirt over Derek's head, checking the reverse of his shirt (one of Stiles’ old ones, as it turns out younger Derek was a tad shorter, and definitely less broad than his older counterpart).

Derek is quiet against his front, although whether it's from shock at the situation or outrage, Stiles can't tell. After a moment or two more though, he finally speaks, his voice muffled by the fabric of Stiles shirt. “What _are_ you doing?”

"Checking for the return policy on immature, kid werewolves."

There's movement against him, before a fist is brought into the flesh of his stomach, and whilst it’s much gentler than Stiles would have expected, it still sends him plummeting off the bed and onto the floor with a jarring thud that would bring his father up the stairs in seconds if he wasn’t already out on shift.

Derek’s expression is unapologetic, even as he leans over the bed to offer Stiles a hand.

“Still not a kid.”

He’s definitely not denying the immature part, and Stiles will take that as a win.

Derek goes back to reading the entirety of the Harry Potter series and Stiles goes back to studying.

He’s making good work of highlighting every other word in his textbook in preparation for Finstock’s annual ‘welcome back’ pop quiz when he hears a thump at the end of the bed, and glances up in time to catch Derek startle awake, his book splayed across the floor about a foot from the bottom of the bed.

“Looks like it’s your bed time, kid.”

Derek bares his teeth, but there's not much heart in it. “Shove it.”

 

**Author's Note:**

> The ending has been left more open/ambiguous, as I was considering writing a sequel, if time allows it in the future..!


End file.
